Screening tube-mill.



J HERMAN.

SCREENING TUBE MlLL.

APPLICATION FILED MAY 9. 1914 1,176,896. Patented Mar. 28, 1916.

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JOHN HERMAN, OF LOS ANGELES, CALIFORNIA.

SCREENING TUBE-MILL.

I Specification of Letters Patent.

Patented Mar. as, rare.

Application filed May 9, 1914. Serial No. 837,403.

-zen of the United States, residing at Los Angeles, in the county of Los Angeles and State of California, have invented a new and useful ScreeningTube-Mill, of which the following is a specification.

My invention relates to tube mills in which the ore or other material is ground by pebbles or other hard substances and discharged through a screen or openings of desired areas. 7

The object of the invention is to provide simple and effective means for grinding and promptly removing the pulverized ore from the machine when it has attained the desired fineness. The unnecessary retention and comminution of ore requires a mill of sequent mixing of the charge, instead of allowing it to slide, is als beneficial in rinding and in protecting the wearing sur- 'ace of the shell. I attain these objects by the mechanism illustrated in the accompanying drawings in which- Figure 1 is a side view of the entire machine; Fig. 2, a longitudinal half section of the machine; Fig. 3, an end view of the machine; Fig. 4, a transverse section of the machine.

Similar letters refer to similar parts throughout the several views.

Fig. 1 shows the tube or drum. mounted on bearings which are hollow trunnions. The letter 8 indicates the screen closely fitted around the drum horizontally; bb, bolts attached to bands to draw the screen closely around the drum; 1), bolts which pass through the ends of the bars which form the shell of the tube or drum and through flanges on the heads of the drum; 3, hollow trunnions on which the drum revolves; p, a pulley which is secured to an extension of one of the hollow trunnions.

Fig. 2 is an end View of the machine, the ends of the bars being indicated by the letter 9; the letter t, indicates one of the hollow trunnions; b, indicates the bolts which. pass through the ends of the bars and the flanges on the head of the tube or drum; bb, indicates a bolt fastened to a band to keep the screen close to the drum, the band being adjacent to the screen and not shown on account of its small cross section, being already shown in Fig. 1.

Fig. 3 is a longitudinal half section on the dotted line shown in Fig. 2; the letter 9*, indicates the bars which form the shell of the'tube ordrum, the bars having decreasing openings between them, the larger areas of the openings being on the inside of the shell; 6, indicates the bolts which pass through the bars and the flanges on the head of the tube or drum; It, indicates the hollow trunnions one of which is extended to carry the pulley which is indicated by the letter 10; 8, indicates the screen.

Fig. 4: is a transverse section on the dotted line shown in Fig. 1. The letter g indicates the bars, two bars constituting a single castmg, which casting is indicated by the letter 9, in Fig. 2; 8, indicates the screen; If shows the opening through the hollow trunnion at the farther end of the tube or drum.

In operation, flint pebbles or other hard substances of suitable shape and size are put into the mill to grind the ore, which is fed into the mill preferably through hollow trunnions. The tube or drum is revolved at a suitable speed. The decreasing openings prevent coarse particles from reaching the screen while any material remaining in the openings will drop down into the charge when the bars are at the higher points. The constant movement of the pebbles or balls causes vibrations of the shell which are imparted to the screen which is in close contact with the outside of the shell, thus aiding gravity in keeping the screen openings from clogging. Where ordinary shaking screens may have two or three jars a second my machine has as many hundred in the same time, thus keeping the screen clean.

The openings of continuously decreasing area in. the bars prevent the coarse pieces from reaching the screen, thus preventing injury thereof; these openings also allow of the mill and the component parts of the preferred form but I do not limit myself to the form or shape of the mill or its parts as shown therein.

It is of importance that the openings from the inside of the shell toward the outside are made of continuously decreasing cross sectional area in order that any particles of ore, such as quartz ore, which have a tendency to becomelodged in these open ings,- may be dislodged and'made to fall back into the grinding zone as the shell revolves. Such action is facilitated by the vibration caused by the grinding ballsor pebbles. The mill is especially valuable in concentrating ores, which will be thoroughly disintegrated to the size desired and Wholly discharged from the mill.

I claim:

1. A grinding and screening mill comprising a rotatable tube or drum horizontally mounted and having openings of continuously decreasing cross sectional area in the shell with the larger area of the openings inside said shell, grinding means in said drum, and a continuous screen circum- .ferentially mounted on the outer periphery as described.

JOHN HERMAN. Witnesses:

MILTON O. STUARD, J on); T. HOGAN. 

